That's interesting, I assumed teachers at private schools would make more.

I think it depends on the school. The very expensive private schools here pay well. I know someone who was making 70k with a masters in their first year. He would have made about 50k -ish in a public school (if he could have gotten a job which is much harder because of union seniority)

Public school teachers have benefits, pensions and union contracts that private schools don't so they often pay more.